In the US, the government does not have laws requiring minimum amounts of vacation. Instead it is between the employer and employee. It varies widely, though I've found jobs requiring more education might average slightly more, vacation amounts might go up slightly with time in a position. Two weeks of vacation to start would not be uncommon - but there is a lot of variation.

In my current company, people start with three weeks and I've been long enough to get closer to five weeks. What I find strange is there are people who don't necessarily use all the vacation they are allowed which I take as more of a cultural phenomenon.

However when it comes to touring, I've been fortunate to take seven long trips totaling more than five years time for extended bike tours (including a one year long trip where I spent 8 months/19491 km perimeter of Australia and other places). That trip and several others I did with a "leave of absence". My longest trip of 18 month to cycle across the Americas I did quitting my job and bring rehired by the same company on return.